One in 20 English beaches that currently pass standards for cleanliness will fail tougher tests, which come in next year, figures show.
Almost all beaches (99.5%) in England meet the basic standards for clean bathing water, with just two spots failing to reach the mandatory grade this year: Lyme Regis Church Cliff Beach, Dorset, and Staithes, North Yorkshire.
But under tougher European standards which come into force next year, 5% of those beaches which are currently reaching the mandatory standards will be classed as "poor", reducing the number achieving the required level of cleanliness to 94.5%. Words: PA
More than 20 beaches are projected not to make the grade, including Blackpool North and Blackpool Central, Lancashire and Seaton and East Looe in Cornwall.
The bathing water statistics from the Department for Environment, Food and Rural Affairs (Defra) showed the number of beaches which reached mandatory levels for cleanliness increased from 98.8% in 2013 to 99.5% this year in England.
In Wales all beaches tested met the mandatory level of cleanliness, in Scotland 97.5% passed bathing water tests and 95.7% of beaches in Northern Ireland made the grade.
The figures also showed that the proportion of beaches reaching existing higher "guideline" standards of cleanliness fell slightly in 2014.
In England, 80.7% of beaches meet the higher grade, a slight drop on 83.5% in 2013. In Wales 88.1% of bathing spots achieved the higher standards, as did 55.6% in Scotland and 69.6% in Northern Ireland - where it fell from 87% the previous year.
Water minister Dan Rogerson said: "Water quality is improving and has now reached a record high, which means families across the country can make the most of what nature has to offer.
"We know that seaside tourism is hugely valuable to the economy, contributing over £3.6 billion every year. That is why it is so important to protect our seas and lakes, allowing our seaside communities to thrive.
"We know meeting the tough new targets is going to be a challenge but that is why we are doing everything we can to help prepare. Everyone has an important role to play, from a range of sectors to local government and the communities they represent."
Dr Paul Leinster, chief executive of the Environment Agency, said: "This year a record 99.5% of beaches passed bathing water quality tests, a dramatic improvement in water quality since 1988 when only 65% of beaches passed.
"Successful work with our partners to reduce pollution has benefited the environment and people.
"While 94.5% of beaches would pass the new tougher water quality standards, the Environment
Agency will continue to urge water companies, local authorities, farmers and businesses to take steps to reduce pollution and protect water quality where improvements are needed."
In Wales all 101 beaches tested met the mandatory water standards, and 89 also made the higher grade.
Carl Sargeant, Welsh minister for natural resources, said: "Our bathing waters are an important natural resource that has environmental, social and economic benefits for the whole of Wales, with our fantastic beaches and beautiful coastlines enjoyed by millions every year.
"I'm delighted to see Wales achieve these excellent results for the 2014 bathing season. We must now continue to work with our partners to build on the high standards we have set so that communities across Wales and beyond can continue to bathe in top quality Welsh water for years to come."
Figures from the Welsh Government also showed all of the country's designated bathing spots met the standards required under the new EU measures, and that 72 beaches reached the top "excellent" standard, and 18 met the "good" grade.